In a switched environment (cat6500), there is a multicast server sending multicast data, but there is no clients. IGMP snooping is enabled on this segment. Every 5 minutes, I see flooding of multicast traffic to all switch ports belonging to the same vlan as multicast server, which lasts for few seconds. Is there a way to stop this periodic multicast flooding to other switch ports?
Yes, it does. It shows them under 'show cam static'. For about 5 mins, you can see that all L2 mac addresses (corresponding to L3 GDA) are on the CAM table. During this time multicast doesn't flow on the ports that do not join those groups. After 5 min period, all the entries corresponding to multicast groups on the CAM table are removed for few secs, and then burst of multicast traffic can be seen on the ports that have not joined, and then everything gets back to normal. I've seen on the cisco TAC web-site something called 'multicast source only subnets' on which it says that cam entries for multicast entries gets flushed every five minutes, and then flooded to all ports momentarily till entries are relearned again, I.E. they point to the multicast router port only.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...